Room IV
This occupies a small area, flanking the West tower, and contains two panels. The first describes the architectural developments of the Porta S. Sebastiano (Porta Appia) from the IIIrd to the Vth centuries AD, as a result of which it acquired it monumental appearance that can still be admired today. The second begin a brief description of the other gates of the wall circuit, which is continued in another panel in the West tower. On the walls are four models, including one of the cross on the keystone of the arch of the Porta S. Sebastiano.
